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Biomedical subjects

R S Mosca

Publications and source records attributed to R S Mosca.

At least 19 recordsLinked to original sources
PubMed1998

Techniques and results in the management of multiple ventricular septal defects.

OBJECTIVE: The management of patients with multiple ventricular septal defects remains controversial. Primary closure, interventional catheter techniques, and palliative surgery all may have a role, and specific management guidelines remain undefined. METHODS: We reviewed the records of all 33 patients with multiple ventricular septal defects undergoing repair between January 1988 and October 1996. Pulmonary artery hypertension was present in 21 patients (group 1), and pulmonary stenosis was present in the remaining 12 (group 2). Closure was accomplished from a right atriotomy alone in most patients, although an apical left ventriculotomy was used for apical defects. Among group 1 patients, the mean age at repair was 5.9 +/- 0.9 months. Major associated anomalies included coarctation (n = 6), straddling tricuspid valve (n = 1), and critical aortic stenosis (n = 1). Reoperation was performed in two patients for residual ventricular septal defects. Among group 2 patients, the mean age at repair was 6.6 +/- 3.2 years. Major associated anomalies included tetralogy of Fallot (n = 2), pulmonary stenosis (n = 4), double-outlet right ventricle with hypoplastic left ventricle (n = 1), and isolated left ventricular hypoplasia (n = 1). Three required reoperation for residual ventricular septal defect. RESULTS: There were no early or late deaths, no episodes of heart block, and no significant residual ventricular septal defects among group 1 patients. All group 1 patients remain free of significant residual cardiovascular conditions at a mean of 23.4 +/- 5.1 months. Among group 2 patients, there was one early death in a patient with double-outlet right ventricle and left ventricular hypoplasia. Complete heart block occurred in two patients and one required late mitral valve replacement. There were no late deaths, seven remain alive without significant residual defects at a mean of 36.2 +/- 8.0 months, and two required transplantation for left ventricular failure. CONCLUSIONS: Primary repair for infants with multiple ventricular septal defects is associated with good late outcomes. The right atrial approach is satisfactory for most muscular defects, although limited apical left ventriculotomy was used for apical defects. Pulmonary artery banding should be limited to patients with complex associated defects.

Abnormalities, Multiple↗
PubMed1998

Resting coronary flow and coronary flow reserve in human infants after repair or palliation of congenital heart defects as measured by positron emission tomography.

OBJECTIVE: Coronary physiology in infants with congenital heart disease remains unclear. Our objective was to better understand coronary physiology in infants with congenital heart disease. METHODS: We used positron emission tomography with nitrogen 13-labeled ammonia to measure myocardial perfusion at rest and with adenosine (142 micrograms/kg/min x 6 minutes) in five infants after anatomic repair of a congenital heart lesion (group I), and in five infants after Norwood palliation for hypoplastic left heart syndrome (group II). The groups were matched for age, weight, and time from the operation. RESULTS: Resting coronary flow in the left ventricle in group I was 1.8 +/- 0.2 ml/min/gm; resting flow in the right ventricle in group II was 1.0 +/- 0.3 ml/min/gm (p = 0.003). Coronary flow with adenosine was 2.6 +/- 0.5 ml/min/gm in group I and 1.5 +/- 0.7 ml/min/gm in group II (p = 0.02). Absolute coronary flow reserve was the same in both groups (1.5 +/- 0.2 in group I vs 1.6 +/- 0.3 in group II, p = 0.45). Oxygen delivery was reduced in group II compared with group I at rest (16.1 +/- 4.2 ml/min/100 gm vs 28.9 +/- 4.42 ml/min/100 gm, p = 0.02) and with adenosine (25.5 +/- 8.1 ml/min/100 gm vs 42.3 +/- 5.8 ml/min/100 gm, p = 0.02). CONCLUSIONS: Infants with repaired heart disease have higher resting flow and less coronary flow reserve than previously reported for adults. After Norwood palliation, infants have less perfusion and oxygen delivery to the systemic ventricle than do infants with a repaired lesion. This may in part explain why the outcome for patients with Norwood palliation is less favorable than for others.

Adenosine↗
PubMed1998

Late fenestration closure in the hypoplastic left heart syndrome: comparison of hemodynamic changes.

BACKGROUND AND OBJECTIVES: Although survival of patients with the hypoplastic left heart syndrome treated by staged surgical palliation has improved, hemodynamic data after fenestrated Fontan operation and after fenestration closure have not been reported in this patient population. We sought to describe the hemodynamic status of these patients at cardiac catheterization performed for the purpose of fenestration closure and to compare these data with data from contemporary patients with other forms of univentricular heart. METHODS AND RESULTS: Hemodynamic responses to fenestration closure during cardiac catheterization were reviewed in 40 consecutive patients, including 20 with the hypoplastic left heart syndrome and 20 with other forms of univentricular heart defects. Hemodynamics before fenestration closure (arterial saturation and pressure, Fontan baffle saturation and pressure, pulmonary capillary wedge pressure, systemic arteriovenous oxygen content difference, and right-to-left shunt fraction) were nearly identical between the two groups. Significant (p < 0.05) changes after fenestration closure included increases in arterial saturation (9%), mean arterial pressure (3 mm Hg), and baffle pressure (1 mm Hg) and arteriovenous oxygen content difference (18 ml/L), with near elimination of right-to-left shunting. Cardiac output decreased by 21% and systemic oxygen transport by 13%, with no differences between the two patient groups. Mean baffle pressures were <17 mm Hg in 32 patients (80%). CONCLUSIONS: Hemodynamics after fenestrated Fontan operation and responses to fenestration closure in patients with the hypoplastic left heart syndrome were remarkably similar to that in patients with other univentricular heart defects.

Adolescent↗
PubMed1997

Tricuspid valve repair in children with hypoplastic left heart syndrome during staged surgical reconstruction.

BACKGROUND: The purpose of this study was to determine the incidence of moderate to severe tricuspid valve regurgitation in children with hypoplastic left heart syndrome (HLHS) undergoing staged surgical reconstruction, to assess the mechanisms responsible, and to evaluate the efficacy of surgical repair. METHODS AND RESULTS: We retrospectively reviewed clinical and echocardiographic data of 59 consecutive patients with HLHS operated on at our institution. Patients with a moderate or severe degree of tricuspid regurgitation (> or =2+) demonstrated by color flow Doppler echocardiography before the hemi-Fontan or Fontan operation who underwent tricuspid valve repair were included. Patients with HLHS and coexisting atrioventricular septal defect were excluded from the study. Severity of insufficiency was graded on a scale from 1 to 4+ by Doppler color flow mapping. Tricuspid valve morphology, degree of tricuspid valve regurgitation, and right ventricular function were assessed before and after tricuspid valvuloplasty. Eight patients (8/59; 14%) were found to have a minimum of 2+ tricuspid valve regurgitation before hemi-Fontan or Fontan operations. In five of eight patients (62%; Group A), the valve was found to be myxomatous, thickened, and redundant. There were multiple regurgitant jets in three of five (60%) patients in this group. In three of eight patients (37%; Group B), the valve had a normal echocardiographic appearance and regurgitation was the result of a lack of complete leaflet coaptation. All eight patients underwent tricuspid valvuloplasty, and all experienced a decrease in regurgitation. In five of eight (62%) patients, there was a reduction in insufficiency of two grades of severity and in three of eight (37%) patients, there was a one-grade improvement. Tricuspid valve stenosis was not documented in any of the patients after tricuspid valvuloplasty. In seven of eight (87%) patients, right ventricular function was assessed as fair before tricuspid valvuloplasty repair and improved to good in five of seven (71%) patients after the procedure. The remaining patient had good function both at baseline and after tricuspid valvuloplasty. CONCLUSIONS: Moderate to severe tricuspid valve regurgitation is a common finding in patients with HLHS undergoing staged surgical reconstruction and can result from either abnormal valve morphology or incomplete leaflet coaptation. Tricuspid valvuloplasty during either the hemi-Fontan or Fontan stages of reconstruction carries a high success rate and is associated with improved right ventricular function.

Child↗
PubMed1997

Ross procedure with aortic root tailoring for aortic valve replacement in the pediatric population.

BACKGROUND: Aortic valve replacement with a pulmonary autograft (Ross procedure) is being applied more commonly in children. Although indications for this procedure have been expanded, the presence of a dilated aortic annulus has remained a relative contraindication. In this condition, the use of an undersized autograft in an enlarged aortic annulus may result in significant aortic regurgitation. METHODS: Among 68 children and young adults undergoing the Ross procedure, 15 (age range, 8 to 24 years) with severe aortic regurgitation or stenosis and an aortic annulus diameter that was at least 2 mm larger than the pulmonary annulus had aortic root tailoring. In this group, the diameter of the aortic annulus measured 26.6 +/- 1.3 mm (mean +/- standard error of the mean), whereas that of the pulmonary annulus was 22 +/- 0.9 mm. The mean annular difference was 4.6 +/- 0.7 mm (range, 2 to 12 mm). The aortic annulus was reduced by excising a triangular wedge of tissue posteriorly from the aortic valve annulus at the level of the commissure between the left and noncoronary cusps extending into the anterior leaflet of the mitral valve. The edges were reapproximated over a calibrated dilator to adjust the final size of the aortic annulus to 2 mm smaller than that of the pulmonary autograft. Circumferential felt strips were not used in any patient. RESULTS: All patients survived and morbidity was limited to one reoperation for bleeding. Doppler echocardiographic examination performed at discharge demonstrated that no patient had more than trace to 1+ aortic regurgitation and none had evidence of aortic stenosis. Over a mean follow-up period of 6.3 +/- 1.5 months (range, 1 to 16 months) there has been no late morbidity or mortality and no progression of aortic regurgitation. CONCLUSIONS: Aortic root tailoring further extends the use of the Ross procedure to patients with excessive aortic annular dilation while maintaining the potential for growth, which is particularly important in the pediatric population.

Adolescent↗
PubMed1997

Modified Norwood operation for single left ventricle and ventriculoarterial discordance: an improved surgical technique.

BACKGROUND: Patients with univentricular hearts and ventriculoarterial discordance with potentially obstructed systemic blood flow continue to pose difficult management problems. The goals of neonatal palliative operations are to control pulmonary blood flow while avoiding pulmonary artery distortion, to relieve systemic outflow tract obstruction, and to avoid heart block. METHODS: Between January 1987 and December 1996, 38 patients with either tricuspid atresia or a double-inlet left ventricle and ventriculoarterial discordance underwent a modified Norwood procedure. Their mean age was 15 days, and their mean weight was 3.4 kg. Aortic arch anomalies were present in 92% of the patients. Morbidity and mortality statistics, intraoperative data, and postoperative echocardiograms were reviewed. RESULTS: There were 3 early deaths (7.8%) and 5 late deaths (13.1%). The actuarial survival rates at 1 month, 1 year, and 5 years were 89%, 82%, and 71%, respectively. Follow-up was complete in all children at a mean interval of 30 +/- 9 months. None of the patients had significant neoaortic valve insufficiency, and 1 patient required therapy for residual aortic arch obstruction. Nine patients (30% of the survivors) have undergone the hemi-Fontan procedure, and 18 patients (60%) successfully have undergone the Fontan procedure. CONCLUSIONS: In this patient population, we recommend the modified Norwood procedure as the neonatal palliative treatment of choice. It can be performed with acceptable early morbidity and mortality, and it improves suitability for the Fontan procedure. It reliably relieves all levels of systemic outflow tract obstruction, controls pulmonary blood flow, and avoids heart block.

Abnormalities, Multiple↗
PubMed1996

Bidirectional superior cavopulmonary connection in young infants.

BACKGROUND: Bidirectional superior cavopulmonary connection (BSCC) has become widely used in patients with univentricular AV connections. However, concerns remain about perioperative morbidity and mortality and about the adequacy of oxygenation after cavopulmonary connection in very young patients. This report examines our experience with BSCC in young infants to evaluate whether young age affects operative outcome, to examine the effect of young age on postoperative oxygenation, and to define the lower age limit for successful use of the procedure. METHODS AND RESULTS: The records of the 85 consecutive patients < 6.5 months old who underwent BSCC from December 1990 through February 1995 were reviewed. The average patient age was 4.8 +/- 1.4 months (range, 5 weeks to 6.5 months), with 13 patients being < 3 months old. There were 5 hospital deaths (6%; 70% confidence limits, 3% to 10%). Pulmonary artery thrombosis occurred in 3 patients (4%; 70% confidence limits, 2% to 7%). Younger age was significantly associated with pulmonary artery thrombosis but not with operative death. Oxygenation (arterial PO2, and oxygen saturation) improved significantly and spontaneously over the first 48 hours after BSCC. Younger age had a significant adverse effect on oxygenation in the early postoperative period (first 48 hours). CONCLUSIONS: BSCC can be performed successfully in infants < 6 months old and as young as 5 weeks old. Within this patient population, younger age is not associated with perioperative death but is associated with pulmonary artery thrombosis and postoperative hypoxemia. We suggest that BSCC may be performed any time beyond the neonatal period in symptomatic patients and may be delayed until 4 to 6 months of age if completely elective.

Female↗
PubMed1996

Outcome-associated factors in pediatric patients treated with extracorporeal membrane oxygenator after cardiac surgery.

BACKGROUND: The use of the extracorporeal membrane oxygenator (ECMO) for postoperative cardiac patients has not resulted in the same high success rate as when ECMO is used for neonates with pulmonary hypertension or pulmonary failure. The reason for this is poorly understood. METHODS AND RESULTS: We analyzed retrospectively all pediatric patients placed on ECMO after surgery for a congenital heart lesion between 1981 and 1995 (n = 64). Patients had a two-ventricular repair (A) or pulmonary blood flow supplied by an aortopulmonary shunt (B) or by a cavopulmonary connection (C). Indication for ECMO was unsatisfactory hemodynamics due to (1) ventricular dysfunction, (2) pulmonary failure, (3) pulmonary hypertension, or (4) a combination or (5) for unclear reasons. Hospital survival was related to these and other factors. Overall hospital survival was 33%; 42% of group A patients survived to discharge, whereas only 25% and 17% survived in groups B and C, respectively. Survival was unrelated to the indication for ECMO but appeared to be lower when ECMO was initiated in the operating room or > 50 hours after surgery. Except for one patient with pneumonia, no patient survived who was on ECMO for > 208 hours. ECMO discontinuation in nonsurvivors was due to neurological (30%) or multiple complications (39%), the lack of return of cardiac function (12%), or other reasons (15%). CONCLUSIONS: This review suggests that the diagnosis of single ventricle, initiation of ECMO in the operating room or > 50 hours after surgery, and ECMO for > 208 hours are associated with patient nonsurvival. Noncardiac complications more frequently led to discontinuation of ECMO than did failure of the return of cardiac function.

Cardiac Surgical Procedures↗
PubMed1996

Collagen content in normal, pressure, and pressure-volume overloaded developing human hearts.

Increased myocardial collagen accompanies pressure overload of the adult left ventricle. This phenomenon is poorly understood in infants. This study compares the myocardial volume fraction of collagen in infants who did not have primary heart disease with infants with isolated pressure overload of the right ventricle (tetralogy of Fallot [ToF]), and with infants with combined volume and pressure overload (aortic valve atresia [AVA]). The distribution of collagen in the neonatal myocardium was also determined. We measured the volume fraction of collagen from right ventricular biopsy specimens of cadaver hearts in normal infants (1 to 9 months old; n = 7), infants with ToF (1 day to 9 months old; n = 9), newborns with AVA (AVA-NB) (1 to 4 days old; n = 5), and older patients with AVA (AVA-I) (5 to 8 months old; n = 5). Myocardium from 3 patients undergoing repair of ToF (6 to 8 months old) was also analyzed. Specimens were stained with Masson's trichrome and myocardial volume fraction of collagen determined by point counting. Myocardial volume fraction of collagen was significantly higher (p = 0.02) in AVA-I patients (8.0 +/- 3.5%) versus normal (3.3 +/- 2.7%), ToF (3.2 +/- 1.8%), and AVA-NB (3.5 +/- 2.3%) patients. There was a tendency for increased collagen in the subendocardium, especially in AVA-I patients (p > 0.05). We conclude that patients with AVA-I have increased collagen relative to normal subjects, patients with ToF, and patients with AVA-NB, and that this increase is greatest in the subendocardium.

Aortic Valve↗
PubMed1996

Comparison of hospital charges for closure of patent ductus arteriosus by surgery and by transcatheter coil occlusion.

Hospital charges for coil occlusion were significantly less than for surgical closure of patent ductus arteriosus, and were reduced over time as experience permitted refinement of the coil occlusion protocol. The expected hospital charges for closure by a coil occlusion strategy, including the charges for surgical closure in patients with failed coil occlusion, was less than the hospital charges for surgical closure strategy under any reasonable estimate of coil occlusion efficacy.

Adolescent↗
PubMed1996

Perfluorocarbon supplementation and postischemic cardiac function.

BACKGROUND: During induced ischemia for cardiac surgery inefficient anaerobic energy mechanisms predominate. Sustaining aerobic metabolism with perfluorocarbon-supplemented blood cardioplegia theoretically could lead to improved postischemic recovery. Therefore we studied functional recovery after myocardial ischemia, comparing perflubron (C8F17Br) supplemented blood cardioplegia to standard blood cardioplegia. METHODS: Nineteen dogs underwent 15 minutes of 37 degrees C global ischemia on cardiopulmonary bypass, followed by 90 minutes of cardioplegic arrest by use of blood cardioplegia with or without perflubron and then 30 minutes of 37 degrees C reperfusion. During ischemia myocardial oxygen tension, temperature, and pH were measured. Postischemic left ventricular recovery was assessed by means of preload recruitable stroke work, exponential end-diastolic stress-strain regression, and preservation of adenosine triphosphate and energy charge. RESULTS: The addition of perflubron, a new shorter half-life, lecithin-emulsified perfluorocarbon, provided superior myocardial protection when compared with standard blood cardioplegia. This benefit was evidenced by significantly increased recovery of preload recruitable stroke work slope (71% +/- 8% versus 42% +/- 9%), decreased myocardial edema, and enhanced end ischemic myocardial oxygen and pH levels. CONCLUSIONS: The reliable oxygen delivery system and endothelial-preserving properties of the perfluorocarbons may prove to be an invaluable asset in addition to standard blood cardioplegia in the preservation of postischemic ventricular function. These data support the further investigation of perfluorocarbon-enriched blood cardioplegia.

Animals↗
PubMed1996

The efficacy and cost of aprotinin in children undergoing reoperative open heart surgery.

We performed a prospective, randomized, placebo-controlled, double-blind trial to assess the efficacy of aprotinin in 61 children (median age 3.7 yr) undergoing reoperative open heart surgery (OHS). Three demographically similar groups were studied: large-dose aprotinin (ALD), small-dose aprotinin (ASD), and placebo (P). Over the first 24 postoperative hours fewer patients in the aprotinin groups received packed red cells (ALD, 53%; ASD, 89%; and P, 95%; P = 0.001), platelets (ALD, 32%; ASD, 50%; and P, 65%; P = 0.04), and fresh frozen plasma (ALD, 16%; ASD, 17%; and P, 60%; P = 0.003) than placebo patients. Most importantly, aprotinin patients had fewer exposures to banked blood components (ALD, median 1 U; and ASD, median 2 U) than P (median 6 U; P = 0.001), with no difference in overall complication rate. Use of aprotinin was associated with a savings in the patient charges for blood components, operating room time, and duration of hospitalization. In conclusion, aprotinin decreased the number of units of banked blood components used during the first 24 postoperative hours in reoperative pediatric OHS. Aprotinin thus decreases the risks associated with exposure to banked blood components and reduces hospital charges.

Aprotinin↗
PubMed1995

Hemodynamic characteristics of neonates following first stage palliation for hypoplastic left heart syndrome.

BACKGROUND: It is widely held that the postoperative course of patients with hypoplastic left heart syndrome (HLHS) after stage 1 palliation is characterized by hemodynamic instability, which in part may be due to excessive pulmonary blood flow. Hence, avoidance of alkalosis and the use of minimally oxygen-enriched inspiratory gas are thought by many to be important, although there is little pertinent published data. This study was undertaken to characterize the postoperative course and to determine whether the FIO2 and blood pH are related to indices of hemodynamic stability in these infants. METHODS AND RESULTS: The postoperative course of 25 consecutive infants undergoing first stage palliation for HLHS were retrospectively reviewed and the following data were obtained: arterial pressure, arterial blood gas measurements, the inotropic agents used, and multiple respiratory parameters. There was one operative death, and 2 patients died within 2 days, but 22 were extubated (mean, 5.2 +/- 4.1 days after surgery). Hospital mortality was 24%. Mean pH was > or = 7.51 for the first 9 hours after surgery and was > or = 7.45 for the entire period. The mean FIO2 was > or = 50% for the first 18 hours. The PaO2 was appropriate (37 +/- 6 mm Hg at 1 hour after surgery, increasing to 45 +/- 5 mm Hg by hour 73). Only modest inotropic support was needed to maintain appropriate blood pressure. CONCLUSIONS: These data suggest that neither alkalosis nor relatively high inspired oxygen necessarily cause hemodynamic instability in these patients. To what extent these results are generalizable is unclear, but they suggest that there is nothing inherent with HLHS that mandates postoperative hemodynamic instability or unacceptable mortality.

Arteries↗
PubMed1995

Single-stage repair of aortic arch obstruction and associated intracardiac defects in the neonate.

The effectiveness of a single-stage anterior approach for the repair of aortic arch obstruction and associated intracardiac defects has not been well evaluated. We therefore reviewed our experience with 60 neonates (median age 8 days, range 1 to 28) who underwent a single-stage repair by way of a median sternotomy at our institution between 1986 and 1994. Nineteen (32%) had coarctation with ventricular septal defect, 18 (30%) had interrupted aortic arch with ventricular septal defect, and 23 (38%) had coarctation or interrupted aortic arch with complex intracardiac anatomy. The arch obstruction was repaired using resection and primary anastomosis in 54 patients, synthetic patch aortoplasty in 3, subclavian flap aortoplasty in 2, and an interposition gortex graft placement in 1. Total circulatory arrest time was 48 +/- 3 minutes (mean +/- SEM). There were 7 early postoperative deaths (11.7%; 70% confidence limit 8% to 16.6%). The 53 survivors were followed for a mean of 23 months (range 1 to 78), for a total of 1,219 patient-months. Recurrent arch obstruction > or = 20 mm Hg has occurred in 2 of 53 patients (3.8%; 70% confidence limit 1.9% to 7.5%); both underwent successful balloon angioplasty. There were 2 late deaths, 1 of which was noncardiac. We conclude that repair of aortic arch obstruction and intracardiac defects by a single-stage approach through median sternotomy can be accomplished with low mortality in infancy, even with associated complex intra-cardiac anatomy. Recurrent coarctation is relatively uncommon and can be successfully managed with balloon angioplasty.

Aortic Arch Syndromes↗
PubMed1995

The management of tetralogy of Fallot with pulmonary atresia and diminutive pulmonary arteries.

Since September 1991, 14 consecutive patients with tetralogy of Fallot, pulmonary atresia, and diminutive pulmonary arteries have undergone staged repair. All patients had multiple aortopulmonary collateral arteries and the ductus arteriosus was absent in 11. Mean sizes of the right and left pulmonary arteries were 2.2 +/- 0.7 mm and 1.9 +/- 0.8 mm, respectively (range 0.5 to 3.0 mm). Eight patients (57%) have subsequently received complete repair. Age at initial procedure (shunt, right ventricle-pulmonary artery conduit, or direct aorta-pulmonary artery anastomosis) in this group was 5.3 +/- 6.8 months. The number of operative procedures to achieve complete repair was 2.9 +/- 0.8 per patient (range 2 to 4). Intraoperative postrepair peak right ventricle-left ventricle pressure ratio was 0.57 +/- 0.17. Six of 8 patients (75%) required additional interventional procedures (mean 1.5 +/- 1.2 per patient) for angioplasty of peripheral pulmonary artery stenoses, coil embolization of aortopulmonary collateral arteries, or intra-operative insertion of intravascular pulmonary artery stents. Mean follow-up from complete repair was 8.7 +/- 8.3 months (range 0.5 to 23.8 months) and is complete. There was one in-hospital death at 45 days, and one late cardiac death at 20.3 months. Six patients had initial palliative operations (unifocalization, right ventricle-pulmonary artery conduit, direct aorta-pulmonary artery anastomosis, or transannular outflow patch) but have not undergone complete repair. Age at initial procedure in this group was 27.9 +/- 56.9 months (range 0.27 to 155 months), and mean follow-up from initial procedure was 10.9 +/- 11.2 months (range 0 to 31.4 months). The operative mortality rate was 33% (2 of 6 patients). There was one late noncardiac death at 5.3 months. Three patients are awaiting further intervention or repair. This experience suggests that complete repair is feasible even in patients with extremely diminutive pulmonary arteries (< or = 3.0 mm). Pulmonary artery growth is facilitated by early (3 to 6 month) establishment of central pulmonary artery flow by right ventricle-pulmonary artery conduit (pulmonary arteries > 1.5 mm) or by direct ascending aorta-pulmonary artery anastomosis (pulmonary arteries < 1.5 mm). Subsequent interventional catheterization and operative procedures as required for pulmonary artery stenoses and coil embolization of collateral arteries allow continued recruitment of central pulmonary arteries and may obviate or minimize the need for unifocalization procedures.

Angioplasty↗
PubMed1995

Intermediate results after complete repair of tetralogy of Fallot in neonates.

From July 1988 through September 1993, 30 neonates with symptomatic tetralogy of Fallot underwent complete repair. Sixteen patients had tetralogy and pulmonary stenosis, 9 had pulmonary atresia, 3 had nonconfluent pulmonary arteries, and 2 had both pulmonary atresia and nonconfluent pulmonary arteries. The median age at operation was 11 days (mean +/- standard error of the mean, 12.6 +/- 2.9 days), with a mean weight of 3.1 +/- 0.1 kg (range 1.5 to 4.4 kg). Preoperatively, 14 patients were receiving an infusion of prostaglandin, 13 were mechanically ventilated, and 6 required inotropic support. Right ventricular outflow tract obstruction was managed by a limited transannular patch in 25 patients, infundibular muscle division with limited resection in 15, and insertion of a right ventricle-pulmonary artery valved aortic homograft conduit in 5 patients. Follow-up was complete at a median interval of 24 months (range 1 to 62 months). There were no hospital deaths and two late deaths, for 1-month, 1-year, and 5-year actuarial survivals of 100%, 93%, and 93%, respectively. The hazard function for death had a rapidly declining single phase that approached zero by 6 months after the operation. Both late deaths occurred in patients with tetralogy of Fallot and pulmonary atresia who had undergone aortic homograft conduit reconstruction, so that the only independent risk factor for death was the use of a valved homograft conduit (p < or = 0.005). Eight patients required reoperation, resulting in 1-month, 1-year, and 5-year freedom from reoperation rates of 100%, 93%, and 66%, respectively. Indications for reoperation were branch left pulmonary artery stenosis in 5 patients, residual right ventricular outflow tract obstruction in 2 patients, and severe pulmonary insufficiency in 1 patient. Independent risk factors for reoperation included an intraoperative pressure ratio between the right and left ventricles of 0.75 or greater (p = 0.01), Doppler residual left pulmonary artery stenosis of 15 mm Hg or more, or Doppler right ventricular outflow tract obstruction gradient of 40 mm Hg or more at hospital discharge (p = 0.002 and 0.02, respectively). This series demonstrates the safety of early hemodynamic repair of symptomatic tetralogy of Fallot in neonates. It also emphasizes the importance of relieving all sources of right ventricular outflow tract obstruction at the initial operation, particularly that located at the site of insertion of the ductus arteriosus, which may be difficult to diagnose in the neonate before ductal closure occurs. The safety and efficacy of valved aortic homograft conduits in neonates requires further investigation.

Actuarial Analysis↗